基于SPI/SPEI的黑龙江省干旱特征对比分析OA

In order to determine the optimal indicator system for drought monitoring in Heilongjiang Province,adapt to meteorological variations more effectively and develop refined drought mitigation strategies.Based on daily meteorological data from 30 stations in Heilongjiang Province,the Standardized Precipitation Index(SPI)and Standardized Precipitation Evapotranspiration Index(SPEI)at different time scales were calculated to compare and analyze the differences between the two indices in drought trend identification and spatial distribution characteristics.The results showed that,Heilongjiang Province exhibited a significant overall wetting trend from 1971 to 2020 with obvious seasonal variations-significant wetting trends were observed in spring and winter,while non-significant wetting trends occurred in summer and autumn.The two indices showed high consistency in trend,but SPEI,affected by evapotranspiration,had a greater fluctuation amplitude than SPI.There were differences in identification sensitivity between SPI and SPEI,SPI reflected more severe droughts in spring,while SPEI was more effective in capturing drought intensity in summer,autumn,and winter.SPI identified extreme droughts and mild droughts more comprehensively,SPEI was more sensitive to severe droughts,and the two indices showed consistent results in identifying moderate droughts.Drought exhibited obvious regional differences in spatial distribution,with significant regulation by topographic factors.High-frequency areas of severe drought were concentrated in the southeastern part,SPEI indicated that the frequency of severe drought was higher in the east than in the west,and significantly higher in plain areas than in mountainous areas,while SPI showed a more uniform distribution of severe drought with weaker intensity.High-frequency areas of extreme drought were located in the northwestern part,where the frequency was significantly higher in mountainous areas than in plain areas,SPI identified a wider distribution of extreme drought,while SPEI generally indicated a lower frequency of extreme drought.Overall,the total drought frequency in Heilongjiang Province identified by SPI was slightly higher than that by SPEI.